The shoulder is a relatively complex body joint having several degrees of freedom and ranges of linear and especially angular motion, i.e., abduction, flexion and rotation. Treatment of a shoulder following an injury or surgical trauma typically requires immobilization of the shoulder, and the arm connected to it, for an extended period of time.
Splint-type devices have been reported for immobilizing and supporting an injured shoulder during the healing process. U.S. Pat. No. 4,896,660 describes an arm support device comprising an upper arm support, a contoured well shoulder anchor, and a lower arm support. The upper arm support is operable to abut against a patient's side and underlies the humeral portion of a patient's arm. The contoured well shoulder anchor includes a contoured sleeve portion and two straps, which releasably connect the well shoulder anchor to the upper arm support. The lower arm support connects to the upper arm support structure and provides support for a patient's forearm and hand. FR 2,727,007 describes an inflatable cushion structure provided with different positioning means, which is applied between a patient's chest and his/her upper arm. FR 2,589722 and U.S. Pat. No. 5,423,333 describe a device for immobilizing a human shoulder, and for supporting the wrist of the arm associated with that shoulder, comprising three inflatable bladders joined together to form a triangular wedge. The wedge is positioned underneath the patient's arm such that one bladder is positioned along the patient's side, and such that the patient's arm rests on another of the bladders. The device is designed in such a way that the patients' arm is maintained in a fixed angle in relation to the thorax of the patient. The angle between the arm and the thorax support is variable, depending on the possibility to fold one of the bladders of the triangular wedge. U.S. Pat. No. 5,236,411 relates to a device for immobilizing the limb of a patient in an elevated position comprising an inflatable member that is adjustable between a deflated state and an inflated state and a harness for attaching the device to the body of a patient. The member is placed between a support surface and the limb of the patient, thus elevating the limb.
Nevertheless, although the above-described devices are suitable for immobilizing a shoulder, they immobilize the shoulder in essentially one position against the body: the arm is immobilized in a particular angle in relation to the thorax, and no further movement of the arm is allowed. Also, these devices do not enable the embraced arm and shoulder to undergo combined movements, which are useful for effective reinforcement of arm and shoulder muscles after injury or surgical operations.
In fact, it has been found that effective rehabilitation requires the recovery of the ranges of angular arm and shoulder motion. A certain degree of mobility of the patient's limbs is required in order not to detract from rehabilitation of the shoulder. In view of this requirement, devices have been developed which enable continuous passive motion of the patient's arm and shoulder of which EP 597,623 and EP 525,930 may be cited as examples.
EP 597,623 relates to an adjustable shoulder brace mountable on the arm and torso to isolate the shoulder and which is fully adjustable across the abduction, flexion and rotation ranges of motion of the shoulder so that it enables fixation of the shoulder in virtually any rehabilitative position. The brace is made up of a series of rigid support members secured to the body of the patient, and a plurality of selectively rotatable and lockable joints adjustably interconnecting the support members. It is said that the combined effect of the joints simulates the entire range of motion of the shoulder. However, due to the presence of a plurality of joints for positioning the shoulder at selected angles of abduction, flexion and rotation, the device is very complex, uncomfortable and difficult to adjust. Also, this device immobilizes the patients' shoulder at a selected angle.
EP 525,930 relates to a passive shoulder exerciser constructed to move a patient's arm back and forth through an arc of up to 180 degrees for providing flexion and abduction of the shoulder. The shoulder exerciser includes a base, an electric drive motor, and an arm holder for the patient's arm, mounted to the drive motor for reciprocal movement by the drive motor through an arc of up to 180 degrees. The arm holder is slidably and pivotably mounted such that during use of the exerciser a patient's arm may slide towards and away from the body and pivot along two pivot points to allow the shoulder joint to follow a natural anatomical range of motion. However, this type of device does not allow all of the essential movements, including combined movements of wrist and elbow. Furthermore, this device is cumbersome and unpractical. As it is not a portable device, the patient needs to go to the location of this exercise and rehabilitation device every time he wishes to use it.
Another shoulder device meant to impart continuous passive motion to a patient's shoulder is described in U.S. Pat. No. 4,651,719. A portable arm and shoulder brace causes abduction and adduction and has the option of causing simultaneous rotation as well through use of a single actuator. An upper arm support is pivotally connected to and extends laterally from the base of the device. A linear actuator extends between and is linked to the upper arm support and the base to cause abduction and adduction of the arm. A forearm support, which is pivotally connected to the upper arm support and angularly adjustable relative to the upper arm support, is linked to the base to cause rotation of the forearm support as the upper arm support is pivoted. The device is contained in a housing having a chamber with an extendable, two-part cover so that the operating mechanism is concealed. However, although portable, this device is rather large and can be uncomfortable.
Many of the above systems also have the disadvantage that they slide off of the body, sliding to the backside of the user which makes them not practical in use.
The presently known devices have several drawbacks. There remains a need for a compact and comfortable orthopedic brace that enables all kind of single as well as combined passive movements of the embraced limb.